Rubble from the tsunami-hit commercial district of the town of Otsuchi in Japan in 2011 (Picture: AFP/Getty Images)

Forget Alien versus Predator, or Tom versus Jerry. Which is more powerful – an earthquake or a volcano?

Researchers studying volcanoes in Japan and Chile have found that so far, earthquakes definitely have the advantage.

They can be so powerful that they cause volcanoes to sink.

The massive Japanese earthquake that caused a devastating tsunami in 2011 appears to have affected volcanoes miles from the epicentre, on the island of Honshu.

A team from the Disaster Prevention Research Institute at Kyoto University found that they have sunk by up to 15cm since the 9.0 magnitude quake.

In Chile, scientists from Cornell University, New York, also found ‘unprecedented subsidence’ of volcanoes up to 130 miles away from the 2010 quake in the Maule region of Chile, which reached 8.8 on the Richter scale.

The researchers used data from satellites to see how the ground around the volcanoes had changed before and after the enormous earthquakes.

However, it’s not clear if the volcanoes are now more likely to erupt as a result.

And the researchers say they don’t know exactly why the volcanoes sunk, though they suggest that it could be due to the earthquake weakening the volcanoes’ internal structure.

Recent eruption: Popocatepetl volcano in Mexico spews a column of smoke and ash 1,500 metres high into the sky on June 25, 2013. (Picture: REUTERS)

Because the damage from a tsunami can often reach across an entire ocean, The Open University’s Dr David Rothery, course leader of Volcanoes, Earthquakes and Tsunamis, says earthquakes seem more dangerous than volcanoes.

‘Certainly in historic times more people have been killed by earthquakes (and by tsunamis caused by earthquakes) than by volcanic eruptions,’ he said.

But, take a long-term view, says Dr Rothery, and ‘some very infrequent volcanic eruptions could throw so much ash and sulphur dioxide into the sky that the whole globe could be plunged into darkness for weeks or months’.

‘That could cause global famine, and even extinction of some species, which are things that no earthquake is likely to lead to,’ he added.

Visit The Open University’s Open Learn pages to learn more about volcanic eruptions. Details of The OU’s Volcanoes, Earthquakes and Tsunamis course can be found here.

You can also take a look at the OU facebook page and join the conversation with students, advisers and academics.